/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#ifndef _tree_h
#define _tree_h
#ifdef	__cplusplus
extern "C" {
#endif

#include "my_base.h"		/* get 'enum ha_rkey_function' */
#include "my_alloc.h"           /* MEM_ROOT */

    /* Worst case tree is half full. This gives use 2^(MAX_TREE_HEIGHT/2) leafs */
#define MAX_TREE_HEIGHT	64

#define ELEMENT_KEY(tree,element)\
(tree->offset_to_key ? (void*)((uchar*) element+tree->offset_to_key) :\
			*((void**) (element+1)))

#define tree_set_pointer(element,ptr) *((uchar **) (element+1))=((uchar*) (ptr))

#define TREE_NO_DUPS 1

    typedef enum {
        left_root_right, right_root_left
    } TREE_WALK;
    typedef uint32 element_count;
    typedef int (*tree_walk_action)(void *, element_count, void *);

    typedef enum {
        free_init, free_free, free_end
    } TREE_FREE;
    typedef void (*tree_element_free)(void*, TREE_FREE, void *);

    typedef struct st_tree_element {
        struct st_tree_element *left, *right;
        uint32 count : 31,
                colour : 1; /* black is marked as 1 */
    } TREE_ELEMENT;

#define ELEMENT_CHILD(element, offs) (*(TREE_ELEMENT**)((char*)element + offs))

    typedef struct st_tree {
        TREE_ELEMENT *root, null_element;
        TREE_ELEMENT **parents[MAX_TREE_HEIGHT];
        uint offset_to_key, elements_in_tree, size_of_element;
        ulong memory_limit, allocated;
        qsort_cmp2 compare;
        void *custom_arg;
        MEM_ROOT mem_root;
        my_bool with_delete;
        tree_element_free free;
        uint flag;
    } TREE;

    /* Functions on whole tree */
    void init_tree(TREE *tree, ulong default_alloc_size, ulong memory_limit,
            int size, qsort_cmp2 compare, my_bool with_delete,
            tree_element_free free_element, void *custom_arg);
    void delete_tree(TREE*);
    void reset_tree(TREE*);
    /* similar to delete tree, except we do not my_free() blocks in mem_root
     */
#define is_tree_inited(tree) ((tree)->root != 0)

    /* Functions on leafs */
    TREE_ELEMENT *tree_insert(TREE *tree, void *key, uint key_size,
            void *custom_arg);
    void *tree_search(TREE *tree, void *key, void *custom_arg);
    int tree_walk(TREE *tree, tree_walk_action action,
            void *argument, TREE_WALK visit);
    int tree_delete(TREE *tree, void *key, uint key_size, void *custom_arg);
    void *tree_search_key(TREE *tree, const void *key,
            TREE_ELEMENT **parents, TREE_ELEMENT ***last_pos,
            enum ha_rkey_function flag, void *custom_arg);
    void *tree_search_edge(TREE *tree, TREE_ELEMENT **parents,
            TREE_ELEMENT ***last_pos, int child_offs);
    void *tree_search_next(TREE *tree, TREE_ELEMENT ***last_pos, int l_offs,
            int r_offs);
    ha_rows tree_record_pos(TREE *tree, const void *key,
            enum ha_rkey_function search_flag, void *custom_arg);

#define TREE_ELEMENT_EXTRA_SIZE (sizeof(TREE_ELEMENT) + sizeof(void*))

#ifdef	__cplusplus
}
#endif
#endif
